Manchester united will play against big teams like Manchester City, arsenal and Barcelona. Manchester United performance is not poor, I think they are ready to play against any tesm with their form of performance.
Manchester City is not in the Europa League so Manchester United will only meet Manchester City in the Premier League or the FA Cup this season. And for Barcelona it is very clear that they will face Manchester United because the play-off match in mid-February will take place at Camp Nou where Manchester United will play away there against Barcelona. So Arsenal doesn't need to be discussed at this point because Manchester United and Barcelona still have to pay attention and need to fight better in the play-off round.
Manchester United will play against Barcelona in the Europa League in the middle of February, while Manchester United will play against Manchester City and Arsenal this month in the Premier League. It doesn't matter if Manchester United play against them in the European League or in the English Premier League because what is clear, these are tough opponents and that is a big match which of course has high tension.
But if Manchester United can produce good results when Manchester United play against these teams, then it is certain that Erik ten Hag has succeeded in building Manchester United for the better.
There is still plenty of time for Manchester United to prepare for matches in the Europa League, because they also have to be careful. Because if a lot of their players are injured then that will be something that is not good, because playing against Barcelona in the Europa League, of course Manchester United must be able to play all the main players.
But at this moment, I really believe that Manchester United is still better and has a chance to qualify for the next round by getting rid of Barcelona.